Drafting apparatus



Sept. 18, 1951 R. F. JESSEN 2,568,502

DRAFTING APPARATUS Filed Feb. 25, 1947 a Sheets-Sheet 1 P 1951 R. F. JESSEN DRAFTING APPARATUS 3 Sheets-Sheet 5 Filed Feb. 25, 1947 Iii || HIHIIIIIIH: H I H 4 d .I ll 1 uxilll H. Q I 1 QN $m- Q 9w T W wru wv u \N Arron/Era Patented Sept. 18, 1951 DRAFTING APPARATUS Robert F. Jessen, Lancaster, S. 0., assignor, by

mesne assignments, to Saco-Lowell Shops, Boston, Mass., a corporation of Maine Application February 25, 1947, Serial No. 730,834

This invention relates to the drafting of fibrous strands in the production of yarn and is concerned more particularly with a novel apparatus for subjecting such strands to long draft.

Spinnin frames containing long draft mechanisms have been in common use for some time for operation on cotton and the conventional frames of this type are restricted to the drafting of stock containing fibers of a maximum staple length, which is relatively short and approximates that of cotton. A mill equipped with such conventional long draft spinning mechanisms can, accordingly, not process fibers 2" or more in length and thus cannot handle uncut worsted fibers or synthetic fibers in the staple lengths usually employed. More recently, long draft .frames designed to handle stock containing long fibers and long draft frames capable of conversion, so that they can handle either short or long fiber stock, have been available, but a mill equipped with conventional long draft mechanisms must either continue to limit its production to short fiber yarn or else scrap that equipment and, at great expense, replace it with equipment designed specially for long fiber operation, or with equipment of the convertible type.

The new drafting mechanism can be incorporated at low cost in present conventional long draft spinning frames and such frames can then be used in the drafting of fibers of much longer staple length than those which the frames were originally intended to handle. Also, the new mechanism can be quickly converted from long to short fiber operation and vice versa. Conventional long draft frames, in which the new drafting mechanism has been installed, can, accordingly, be used for the handling of either cotton fibers, synthetic fibers up to about, 3" long, or worsted fibers up to about 3 /4" long. The apparatus offers the further advantage that yarn made from long fibers by its use is substantially stronger than that made by prior long draft equipment designed for handling such fibers.

In the new drafting mechanism, the strand to be drafted is gripped tightly by pairs of rolls having a spacing between their nips, which is substantially greater than the staple length of the fibers in the strand, the front rolls operating at a surface speed many times, for example, 18 or 20, that of the back rolls. A length of the strand lying between and spaced from the nips of the rolls and terminating close to the front rolls is supported on a traveling surface moving at a speed greater than the surface speed of the back rolls, and the fibers in the length of the strand so supported, are controlled by pressing the strand 4 Claims. (01. 19-131) lightly against that surface. Fibers gripped by the front rolls can, accordingly, be drawn forward thereby past the point of application of the pressure on the strand without damage, while those not so gripped are held back. Uniformity in drafting is obtained partly by the application of the light pressure to the supported length of the strand and partly by the contact of the strand with the supporting surface. The traveling supporting surface is provided by means of an endless apron, having a stretch extending parallel to the path of the strand, and, in order that the apron may be advanced at the proper rate, it is passed over a driven roll at the rear end of the stretch, and its edges are pressed tightly against the driven roll. The control pressure is applied to the strand over the central part of the apron above the driven roll, as well as elsewhere along the stretch of the apron lying parallel to the strand.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which: Figure 1 is a top plan view of one form of the new apparatus;

Figure 2 is a sectional view on the line 2-2 of Figure 1;

Figure 3 is a view in side elevation of a top roll employed in the new apparatus;

Figure 4 is a sectional view on the line 4-4 of Figure 3;

Figures 5 and 6 are sectional views on the lines 55 and 6-6 of Figure 3; and

Figure 7 is an end view of the roll shown in Figure 3.

The new drawing mechanism illustrated in Figures 1 and 2 is suitable for use on a spinning frame and includes the usual roll stand ID provided with bearings, in which three driven bottom rolls II, l2, and I3 are mounted. The rolls are bare and made up of sections connected end to end, so that the rolls extend the length of the frame, and rolls II and I3 are fluted, while roll I2 is knurled. Top rolls [4 and I5 cooperate, respectively, with front and back bottom rolls H and I3, and the top rolls, each of which has two bosses, are covered with any of the usual roll coverings, and have ends received in pockets in cap bars I'6 attached to a shaft 11.

A plurality of top rolls [3 are mounted in alignment along the frame to cooperate with the intermediate bottom roll [2 and each to roll has two bosses and includes an arbor l9, the ends of which enter pockets in the cap bars. Collars 20 are mounted near opposite ends of the arbor rol I tand- .angular form andhas a flat. surface parallel. to ,aagplane-tangent to the tops of the frontandinl9 and are held in place by set screws 2|. Midway of its length, the arbor carries a sleeve fast thereon. the sleeve being formed with a central neck 22 and enlarged hubs 23 at its opposite ends. A floating boss 24 is mounted on the arbor between each hub 23 and the adjacent collar and the-bosses 24 havean axial-boreof substantially greater diameter thangthat of the ;,arbo;r. The collars 20, hubs 23, and floating bosses 24 are of the same external diameter and they are all provided with suitable coverings 25. Preferably, the floating bosses have only a limited freedom of rotary movement relativeto -the col lars and hubs and, for thispurpose, each boss is provided with pins 26, which projectoutwardly.

beyond its ends and are receiyable in enlarged pockets 2'! and 28 in the opposed ends of-collars 20 and hubs 23, respectively. The floatingbosses can be held against movement relative to the glrbonby, adjusting the collars 20 angularl about the arbor and securing them in position by set crews-2-l with pins 26 clamped between the op.-

posite sides of openings 2] and 28. When the ;pantsare in this condition, the roll. 18 operates min-the manner of an ordinary toproll. If desired, -=the,pins 26 'may be omitted from the bosses, in .which event the bosses will be rotatedby contact .withthe stock being drafted and will not-neces .sarily rotate in unison with the hubs, between .w ichthey-lie.

apron 29, made of leather or a suitable .synthetic material, is led about theintermediate ;.b ottorr 1 .-roll l2, a nose bar 30 fixed in position in -agg y suitable mounting, and -a flanged tension roll 31 mounted i 'a bracket 32 attached to the The nose bar" isof generally triiermediate bottom rolls II and 12, so that the :apren has a stretch-33 lying parallelto the path of thestrand through the mechanism. The. nose mines close to the nip of rollsl-l' -and lll and v -a lighttselfrweighted roll 3.4, havlnglends bearing against nibs on the cap bars, restsfupon"the -..g.pr onabove the nose bar.

A back saddle 35 bears against the neckof roll-J5 .betweenthebosses thereon and upo'nthe neck 22 of roll [8. Afrontsaddletfi bearshatone pnd againstsaddle. 35 and, at theotherend,

against the neck of roll M between the bosses thereon. A stirrup 3-1 is. connected to the front saddle 36 and a weightedlever 38 passes through ..-the opening at the-lower end of the stirrup. fIhe leve'r'has a nose attached to the roll'beam 39 by a lover-screw and the weight 4| is conneetedto the opposite endpf the lever by a hook The strand 43, which, in the case .of aspin- A ning frame, is a roving, is led from a bobbinin thecreel through a trumpet. on the usual traverse. bar 4.5-and between rolls [3 and 15, which grip i-t tightly. If the yarn is to be spun ffrom double roving, the two rovings'aregdrawn from their bobbins in the creel and ledthrough the same trumpet. From rolls l3 and |'5,'the strand passes to the upper surface of the stretch p33of'the apron and beneath the floatingboss -24 of roll l8. The strand lies in C ntact withthe stretch 33 of the apron throughout the length ef the stretch and passes-beneath roll '34 to the front rolls H and I4. I

In the operation of the new drafting-mecha- --nism described, the intermediate rolls I2 and I8 and apron 29 have a surfacespeed greater-than the surface speed of the back .or: retaining; rolls If'r,ol1 l8 werewholly floating and thus similar rolls.

l3 and I5, as, for example, the surface speed of the intermediate rolls and apron may be about 1.30 times that of the retaining rolls, as is conventional in long draft mechanisms operating on cotton. However, the intermediate rolls and apron may be operated at a higher surface speed,

vi frdesirled. The drawing rolls II and [4 are opergated at a surface speed man times, for example, 16 or more, the surface speed of the back i The roving is thus drafted between the back and front rolls and the floating boss 24 of-theintermediate top roll and the self-weighted roll .34 press theroving against the apron for control purposes. The floating boss and roll 34 permit-free passage of fibers, which are gripped by the drawing rolls H and I4 and advanced rapidly thereby, and at the same time control the trailing ends of such fibers. The floating boss and roll 34 restrain those fibers which are not gripped by the drawing rollsbut would otherwise be drawn along by contact with fibers which are so gripped. The collar 20 and hub 23 on roll I18 press the edges of the apron tightly againstthe driven bottom roll [2, and the apron is thus advanced at the samesurface speed as roll 12.

to the self-weighted roll 34, the apron would not be advanced at the proper rate merely by its contact with roll '12. On the other hand, if roll 30 gages, the rovingmerely controls the fibers therean indication of the superior performance ,of the new mechanism, the following test results be given: A spinning frame equippedwith the. newmechanism was supplied with zoo-hank fra in made of a blend of 80% B'denier '2" viscose and 20% 64s worsted top out 2? with two ends of roving passing to each set of rolls. ,The roving was spun into an lSs/l yarn, using 'pf.. 3.50 twist multiplier and, sincetwo .ends of roving were supplied to each set of rolls,'the

. dra wa T i t of t floet n bos ".2! of the intermediate top roll was 832 grains.

yarn so produced had a strength factor: of "1336, whereas the best yarn produced from the e blend on a standard commercial frame designed for 2" staple and operating under the conditions above set forth, had a strength faQtor r szo.

A 2Qs/ 1 yarn produced on a frame equipped with the new draft mechanism from double creeled ZOO-hank roving of the blend above describedwith a draft of 20, using a twist multiplier of 3.50,.had a strength factor of 1293. The

bestZOs/I yarn'produced on the standard, corn- 'rnercial frame had astrength factor of 1220..

' Inthe production of yarns in the tests above set forth, thensurface speed of the aproniwas L30 times that of the back rolls but, since the r floatingbossfll does not provide sufficient pressure .to effect a break draft, it was found desirable to use a roving twist slightly lower than that which could have been used, if a break draft hadbeen employed.

- Jn conventional long" draft mechanism for operation on cotton, the roving is gripped t ghtly by the back rolls, the intermediate rolls, and the front rolls, so that the distance between the nips of the front and intermediate roll limits the maximum length of the fiber that can be handled. In such conventional mechanisms, it is necessary that the intermediate roll be weighted, in order that the single apron or the two aprons will be driven at the proper surface speed by the intermediate bottom roll. In the new drawing mechanism in the form shown in Figure 2, the use of the intermediate top roll with the floating boss makes it possible to apply sufficient pressure to the apron to insure that it will be driven at the proper surface speed by the intermediate bottom roll, but the relatively light floating boss applies only control pressure to the strand at the rear end of the active stretch of the apron and does not contribute to the drive of the apron. Accordingly, the mechanism can handle stock in which the fibers have a staple length only slightly less than the distance between the nips of the front and back rolls. A frame equipped with the floating boss roll may be converted to conventional long draft operation on short fibers merely by adjusting and setting the collar on the roll to clamp the floating boss and prevent it from floating. When the mechanism has been employed in such form, the conversion back to a form permittin the handling of long fibers requires only another adjustment and setting of the collar to free the boss and permit it to float.

I claim:

1. A drawing mechanism for use in textile frames having retaining roll tightly gripping the strand to undergo draft and drawing rolls tightly gripping the strand and rotating at a surface speed substantially higher than that of the retaining rolls, the combination of an apron having a stretch lyin beneath and parallel to the strand as it passes from the retaining rolls to the drawing rolls, said stretch of the apron supporting the strand in the drafting zone and being spaced from the nips of the retaining and drawing rolls,'means for advancing the apron at a surface speed between those of the retaining and drawing rolls, said means including a driven roll within the apron and a roll having end portions pressing the edges of the apron tightly against the driven roll and a relatively light cylindrical central portion floating relatively to the end portions and adapted to rest upon and press the strand against the apron, a bar within the apron supporting it with the forward end of said stretch close to the nips of the drawing rolls, and a light roll adapted to press the strand against the apron above the bar, the light roll and said light central portion being operable to restrain fibers not gripped by the drawing rolls, while permitting free passage of fibers, which are gripped by the drawin rolls.

2. In a drawing mechanism for use in textile frames having retaining rolls tightly gripping the strand to undergo draft and drawing rolls tightly gripping the strand and rotating at a surface speed substantially higher than that of the retaining rolls, the combination of an apron having a stretch lying beneath and parallel to the strand as it passes from the retaining rolls to the drawin rolls, said stretch of the apron supporting the strand in the drafting zone and being spaced from the nips of the retaining and drawing rolls, and means for advancing the apron at a surface speed between those of the retaining and drawing rolls, said means including a driven roll within the apron, a top roll having end portions pressing the apron tightly against the driven roll, a floating boss between the end portions and driven thereby, and means connecting the boss to the end portions for limited freedom of angular and radial movement relative to the end portions and operable to secure the boss rigidly to the end portions, the floating boss being operable to restrain fibers not gripped by the drawing rolls, while permitting free passage of fibers, which are gripped by the drawing rolls, and weighting means acting on said top roll.

3. In a drawing mechanism for use in textile frames having retainin rolls tightly gripping the strand to undergo draft and drawing rolls tightly gripping the strand and rotating at a surface speed substantially higher than that of the retaining rolls, the combination of an apron having a stretch lying beneath and parallel to the strand as it passes from the retaining rolls to the drawing rolls, said stretch of the apron supporting the strand in the drafting zone and being spaced from the nips of the retaining and drawing rolls, a bar within the apron supporting it with the forward end of said stretch close to the nip of the drawing rolls, a driven roll within the apron at the rear end of said stretch thereof and having a surface speed between those of the retaining and drawing rolls, a top roll mounted above the driven roll and having end portions pressing the edges of the apron against the driven roll, a floating boss mounted between the end portions, and means connecting the boss and end portions to cause .the boss to rotate with the end portions while having a limited freedom of angular and radial movement relative thereto, weighting means for said top roll, and a self-weighted roll lying above said stretch of the apron, said boss and self-weighted roll being adapted to press the strand against the apron to restrain fibers not gripped by the drawing rolls, while permitting free passage of fibers, which are gripped by the drawing rolls.

4. A roll for use in textile frames which comprises an arbor, end members mounted on the arbor in spaced relation, the end members having cylindrical surfaces concentric with the arbor and one member being fast on the arbor, while the second is angularly adjustable relative thereto, means for holding the second end member in selected angular relation to the arbor, a boss mounted on the arbor between the end members and having a cylindrical outer surface and a passage, through which the arbor extends, which is of substantially greater diameter than the arbor, and pins projecting beyond the ends of the boss axially thereof, the end members having openings in their opposed faces receivin the pins and of substantially greater diameter than the pins.

ROBERT F. JESSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,799,448 West Apr. 7, 1931 2,027,212 Truslow Jan. 7, 1936 2,074,556 Pilz Mar. 23, 1937 2,255,821 Schlipp et a1 Sept. 16, 1941 2,471,057 Bird May 24, 1949 

